[Joe Rutledge]

Jimbo was correct on the timing issue. FE's with original heads tended to like lots of total timing (around 38 degrees total). There usually was a significant power difference (less power) between lets say 34 degrees total and 38 degrees total. So you when setting your initial timing needs you have to keep in mind your total timing needs when having the distributor curved. Obviously, if you are going to cut it very close (37/38 total), you had better be damn sure the timing damper is properly marked/indexed. With stock type dampers, it was not that unusual that they were not.

This discussion assumes you have the proper octane for the compression you are running. Running higher compression than street gas allows and compensating for it by retarding the timing often results in less power than proper compression (for the street) with proper advance.

As Jimbo said, I think it is fair to assume that the modern aluminum heads from Dove, Edelbrock, and Shelby may change the total timing requirements somewhat based both on improved chamber design/plug location, and the material as well (However, they still are all "Wedge" head designs, with the chambers being very close to MR heads (except for the DOVE CJ based stuff). Hopefully, the head manufacturer can lend some insight on this subject.

Modern cam profiles may change some of this also?